Vehicle wireless alarm system

1. A vehicle wireless alarm system comprises a front car subsystem installed in a front car and a rear car subsystem installed in a rear car; the front car being in front of the rear car; wherein the front car subsystem comprising: a reverse car sensor and a brake car sensor; an alarm source receiving signals from the reverse car sensor and the brake car sensor; an oscillator receiving signals from the alarm source for mixing the receiving signals with carriers signals; an encoder receiving signals from the oscillator for encoding the receiving signals; an amplifier receiving signals from the encoder for amplifying the input signals to have a larger power for transmission; and a transmitter for receiving the signals from the amplifier for emitting the receiving signals wirelessly as emitting signals; the rear car subsystem comprising: a receiver receiving the transmitting signals from the transmitter; an amplifier receiving signals from the receiver for amplifying the signals; a decoder for receiving signals from the amplifier for decoding the receiving signals; an output device receiving signals from the decoder and outputting the receiving signals; and an alarm device receiving signals from the output device and emitting alarm signals; wherein by above system, a driver in the rear car knows that the front car now reverses or brakes.

2. The vehicle wireless alarm system as claimed in claim 1 , wherein the alarm signals are selected from one of speech signals, light signals, or texts.

3. The vehicle wireless alarm system as claimed in claim 1 , wherein in a first operation mode, the front car is installed with the front car subsystem and the rear car is installed the rear car subsystem, the rear car receives the signals from the front car and display the signals.

4. The vehicle wireless alarm system as claimed in claim 1 , wherein in a first operation mode, the front car is installed with the front car subsystem and the rear car is installed the front car subsystem and the rear car subsystem; the rear car receives the signals from the front car and displays the signals; when the rear car is reversed or braked, the rear car transmits alarm signals to a car at a back side.